赤泥中含铝矿物特征分析及回收试验研究

通过对赤泥进行全组分分析及矿物组成分析得出，赤泥中的铝主要以独立矿物的形式赋存于霞石、钙铝石、加藤石、一水软铝石、高岭石、钾长石、绿泥石中。矿物间共生关系复杂，相互包裹、连生。对赤泥开展反浮选脱硅选矿试验，得到三氧化二铝品位31.17%，铝硅比为3.38的铝精矿，三氧化二铝回收率为21.23%。     

基于矿物结构的高铝黏土矿选择性磨矿分析

通过对我国一水硬铝石-高岭石型高铝黏土中主要矿物的结构与形态及矿石硬度的分析,指出高铝黏土矿含铝矿物和铝硅矿物之间存在可磨性差异。对我国典型高铝黏土矿石进行湿法磨矿及浮选试验表明：湿法磨矿产品中-0．010mm粒级质量分数为38．33％,其铝质量分数比其他各粗粒级产品的铝含量低2～9个百分点;浮选产品中不论是精矿还是尾矿-0．010mm粒级的铝含量较其他各粒级均低3％～6％。说明两种矿物之间确实存在可磨性差异,这种可磨性差异可以作为高铝矾土选矿中磨矿工艺参数选择的基础。     

伟晶岩型锂辉石矿浮选研究综述

基于对伟晶岩型锂辉石矿资源现状,锂辉石矿中主要组成矿物的理化性质与可浮性,锂辉石矿浮选基础研究和工艺现状的分析和总结,指出了伟晶岩型锂辉石矿浮选过程中的主要影响因素及所面临的主要问题。主要影响因素包括:磨矿细度、矿泥及易浮杂质、水质影响、搅拌强度、温度影响和合理用药;所面临的主要问题表现在:锂辉石矿中主要矿物浮选行为的研究有待加强、浮选捕收剂的捕收性和浮选分离抑制剂的选择性有待进一步提高、矿泥的浮选行为及其对锂辉石浮选行为的影响以及矿泥高效处置技术的研究有待加强、高海拔地区锂辉石矿浮选行为及其影响因素有待加强研究。提出锂辉石矿浮选应着重对锂辉石浮选动力学、锂辉石浮选药剂构效关系、泥质矿物浮选行为及对锂辉石浮选行为影响等方面的研究。     

云南某堆积型低品位铝土矿浮选脱硅试验研究

对云南某堆积型高铁高钛低品位、低铝硅比型铝土矿进行了正浮选脱硅试验研究,系统的条件试验表明使用300 g/t六偏磷酸钠和500 g/t硅酸钠的组合抑制剂,同时使用自主研发的捕收剂BC-3为捕收剂,可有效地改善浮选效果;浮选闭路试验获得了精矿铝硅比为7.96,Al2O3回收率为61.09%的浮选结果;为该难选铝土矿资源的开发利用提供一种新的方法。     

铝盐对独居石的抑制作用

铝盐在氟碳铈矿与独居石浮选分离中起着非常重要的作用。本文针对独居石单矿物和氟碳铈矿与独居石混合精矿，通过浮选试验论述铝盐对独居石的抑制作用。     

混合型铝土矿浮选脱硅试验研究

试验以俄罗斯某一水软铝石、三水铝石和一水硬铝石三种铝石混合型低品位铝土矿为研究对象,其关键技术是有效脱除非目的矿物如高岭石、绿泥石和伊利石。研究以矿石性质人手,结合以前的经验,以中国铝业郑州研究院开发的BKS-1为捕收剂,采用正浮选脱硅工艺技术提高矿石的铝硅比。通过多因素条件试验优化了适宜的工艺条件,当综合磨矿细度为90％,pH为9．5,六偏磷酸钠用量100g／t,BKS-1捕收剂用量为800g／t时,获得精矿铝硅比7．31,氧化铝回收率68．61％的工艺指标。     

堆积型铝土矿的浮选技术研究

本文以云南堆积型铝土矿为研究对象开展选矿试验研究工作。铝土矿原矿Al_2O_3品位47.70%,SiO_2品位11.08%,A/S为4.31。在研究了该矿石化学成分与矿物组成的基础上,进行了正浮选一水硬铝石、从而提高铝硅比的试验研究,最终得到Al_2O_3品位54.69%、回收率达到80.69%的精矿,A/S为8.31。本文的研究成果表明,铝土矿的浮选工艺相对简单,高效捕收剂H2的使用是堆积型铝土矿浮选技术的关键。     

金属离子对矿物浮选行为影响的研究进展

在矿物浮选过程中,由于矿物的粉碎溶解、药剂的添加、回水的循环利用等原因,矿浆中难免会存在一些金属离子,这些金属离子往往会对矿物的浮选行为产生重要影响.在对相关文献分析和总结的基础上,概述了金属离子对氧化物矿物、硫化物矿物、硅酸盐矿物浮选和分离的影响.金属离子在不同pH条件下会形成络合物或沉淀,通过消耗捕收剂,抑制捕收剂分解来抑制矿物浮选,矿浆中离子浓度增大到一定程度也会抑制矿物浮选,单种离子不同组分或不同离子组合对浮选效果有较大影响.      

水杨氧肟酸浮选锡石,石英和方解石的研究

研究了水杨氧肟酸对锡石，石英和方解石浮游性以及羧甲基纤维互钠对矿物的抑制作用，同是还考查了金属离子对矿物浮选行为的影响。结果发现，水杨氧肟酸是锡石的良好捕收剂；羧甲基纤维素钠可以抑制方解石；Ｆｅ＾３＾＋，Ｃａ＾２＾＋和Ｆｅ＾２＾＋对浮选有明影响。     

添加水化铁酸钙拜耳法新工艺溶出规律及机理研究

在添加水化铁酸钙的条件下系统进行了溶出中低品位铝土矿试验,结果表明,随水化铁酸钙添加量增多,溶出赤泥铝硅比、钠硅比降低;随配矿量减少、溶出温度升高、溶出时间延长,溶出赤泥铝硅比降低。在温度260℃,时间60 min,使用水化铁酸钙添加剂,得到了赤泥铝硅比为0.74、钠硅比为0.24的较好溶出结果。通过对溶出赤泥进行衍射、扫描电镜和能谱分析,表明赤泥中硅矿物以铁取代铝的水化石榴石为主,Al2O3的饱和系数为0.2左右,Fe2O3的饱和系数为0.7左右,SiO2饱和系数接近1,硅矿物组成改变是赤泥铝硅比和钠硅比降低的原因。     

Grain size and porosity of cast hypoeutectic aluminium-silicon alloys in hexachloroethane coated mould

This paper examined the effect of concentration of hexachloroethane (C₂Cl₆) in alumina mould wash on the grain size and apparent porosity of cast hypoeutectic aluminium silicon alloy. A hypoeutectic aluminium-silicon alloy was prepared and cast in metal mould coated with alumina slurry to which varied concentrations (0–40 wt %) of volatile organic compound, C₂Cl₆, have been added. The effects of the amount of the hexachloroethane in the mould coating on the grain size and apparent porosity of cast hypoeutectic aluminium-silicon alloy were assessed. There was an observed initial decrease and subsequent increase in the grain size as the concentration of C₂Cl₆ in the mould wash increased while there was no significant change in the apparent porosity of the cast alloy. It was concluded that coating metal mould with alumina mould wash containing approximately 15 wt % C₂Cl₆ produces optima grain size. The study also revealed that the use of such volatile mould coating does not introduce any noticeable gas porosity in the cast hypoeutectic aluminium-silicon ingots but rather aids the expulsion of possible trapped gases.     

Aluminium grain structures in Al-Si eutectic alloys

X-ray diffraction evidence is presented to support the contention that the aluminium phase in the aluminium-silicon unmodified flake-silicon eutectic is polycrystalline as solidified. In association with published evidence of preferred oritentation relationships between the eutectic phases, it follows that the aluminium phase is repeatedly re-nucleated on the silicon flakes as substrate during growth of the unmodified eutectic.     

连续热浸镀铝硅钢板镀层微观结构研究

 热浸镀铝硅钢板具有优良的耐热性、耐腐蚀性、耐高温氧化性,目的是研究铝硅镀层钢板的镀层微观结构和性能。利用热镀锌模拟器在实验室条件下制备了热浸镀铝硅镀层钢板,通过扫描电镜、电子探针对镀层的微观组织结构、镀层中元素的平面分布进行了观察,利用X-射线研究了铝硅镀层的物相组成,利用盐雾试验研究了镀层钢板的耐腐蚀性能。结果表明,铝硅镀层由占主要富铝的树枝晶、树枝晶间的铝硅二元合金、铁铝界面层及分布于基体中的块状相组成,镀层组织均匀,结合较好,耐蚀性优良。     

Surface modification by means of laser melting combined with shot peening: A novel approach

Among the available laser applications laser surface melting has turned out to be a powerful technique for the production of wear-resistant layers. Despite the advantages of this process, laser surface melting results in tensile stresses which may assist crack propagation. In this paper it will be shown that shot peening can overcome this drawback effectively. It turned out that a preceding laser treatment of an eutectic aluminium-silicon alloy is able to amplify considerably the effectiveness of the shot peening treatment. In particular the maximum attainable hardness and compressive stress increase upon increasing the quench rate, i.e. upon increasing the laser scan velocity. The high concentration of silicon in solid solution turned out to be the main reason for the enhanced mechanical performance, not only directly through solid solution hardening, but also by precipitation hardening and by a higher dislocation density. The latter contribution is affected indirectly by a changed cross slip behavior.     

About the shape of eutectic grains solidifying in a thermal gradient

In eutectic alloys solidified in a thermal gradient, it has been observed that the final shape of the grains nucleated in the bulk of the liquid is more elongated in the direction opposite to that of the heat flow. This experimental result appears to be in contradiction with that expected for the growth of an isolated grain, since the portion of the interface located in the downstream heat flow direction is the most undercooled and thus has the highest growth rate. However, when considering a family of grains which continuously nucleate in the bulk of the liquid, it is shown that the impingement of the grains limits their growth in the downstream heat flow direction and thus explains their final shape. In order to investigate this phenomenon, the differential equation which governs the growth of an isolated eutectic grain in a thermal gradient has been derived and solved analytically for the two extreme positions of the interface along the heat flow direction. Using these relationships, the asymmetry factor of the grains has been deduced as a function of the solidification parameters. The overall shape of an isolated grain has also been predicted using numerical integration. Finally, these results are integrated into a stochastic model of grain structure formation and the simulated microstructure is compared with experimental micrographs previously obtained for hypereutectic aluminium-silicon alloys remelted by laser.     

缅甸某砷质金矿中金的氰化浸出的研究

缅甸某砷铜炭质金矿中的金系难浸矿物之一。直接用碳浆工艺氰化浸出金的浸出率为60%。矿物中的铜在氰化过程中易形成Cu(CN)2 沉淀覆盖在矿物表面上,阻碍金的进一步氰化反应。研究中在金矿石中添加助浸剂后,矿石中的一些矿物与之反应,使金的氰化速度增加,浸出率达到了90%-92%。     

Influence of Mineral Composition on the Simple Shear Response of Sands: Experimental Study

Experiments were conducted to evaluate the role of mineral composition on the direct simple shear response (i.e., volume change during shear) of uniform sands composed of “strong” quartz grains and “weak” calcareous grains. The dry specimens were loaded in a custom-made direct simple shear apparatus and separated after testing with respect to grain size by sieving and with respect to mineral composition by dissolving the calcareous grains retained on each sieve. The results indicate that the presence of weak grains affects the direct simple shear response of predominately strong-grained sands: at low stresses, the response is controlled by particle shape; at high stresses, the response is controlled by weak particle breakage.     

A cluster of childhood leukemia near a nuclear reactor in northern Germany

Various methods for evaluating bone mineral in appendicular, and axial bone or in the whole skeleton have recently become available. As bone mineral is one of the major determinants of bone strength, its exact measurement should be useful for the diagnosis of osteoporosis, as well as for the prediction of fracture risk and monitoring of therapeutical response. The aims of this paper are to review the fundamental performance of bone mineral measurements, the improvements in DXA systems, and the progress in site-specific bone mineral instruments for the radius and calcaneus used in Japan, and to introduce diagnostic criteria for primary osteoporosis, and report on annual rates of bone loss in Japanese females.     

地质矿产勘查理论与技术分析尝试

随着我国社会的发展,经济建设的脚步加快,对矿产资源的需求也越来越大。矿产资源本身就是一种珍贵的财富,矿产资源的转化更是能为民众创造财富。但地质矿产勘查并不是一件容易的事情,它本身虽然有较高的回报率,但也有较高的风险性。对于长期处在地质矿产勘查一线的工作人员来说,他们的生命安全问题一直是地质矿产勘查过程中迟迟难以解决的问题。倘若地质矿产的勘查技术能够更加先进,那么我国的地质矿产勘查效率将会更上一层楼。本文就是对地质矿产勘查理论与技术的分析与研究,希望通过分析研究来对地质矿产的理论与技术两方面做一个整合。     

Properties of Magnetic Nanoparticles about Doped Rare Earth and Its Composites

The magnetic liquid was prepared with ferric salt by inorganic gel technology. The effect of the doped rare earth elements on the properties of magnetic particles was analyzed. The magnetic liquid was composed with clay mineral into magnetic mineral composites. The crystal structure and micro-morphology of the nanoparticles were studied by XRD and TEM. The results show that the crystal structure of the magnetic particles doped 0.5 % of lanthanum is more complete, and the magnetic response capability is higher with doping agent. At the same time, the possibility of the clay mineral magnetic composites as the carrier of target drug was probed.